Only share titles and dates you are comfortable sharing. Anyone with the link can read them. The link uses a fragment; this app sends no countdown data and saves nothing. A local file link works only on a device with the same files.
A countdown to one moment
The target uses the selected named time zone and its rules in your browser. Skipped times are rejected; repeated times require an explicit choice. The remaining duration is recalculated from your device clock on every update and when you return to this tab. Days mean 24 elapsed hours. Device clock accuracy matters.
Open an explicitly created share link to restore the countdown after reloading. Birth dates from the age tool are never added to countdown links.
EXAMPLES & HELP
Make a countdown to a date and time
A countdown needs a specific moment, not just a calendar day. Set the event’s date, clock time and named time zone so people in different places can count toward the same instant.
How to use this calculator
Give the event a title and choose its target date and time.
Choose the place whose local clock defines the event. Resolve an earlier or later occurrence if a clock change repeats that time.
Create the countdown. Use the optional sharing control only when you want a link containing the event details.
Worked examples
These examples use fixed moments. A running countdown uses your device’s current clock, so its remaining time keeps changing.
Midnight in New York
Start with
Event: New Year. Target: 1 January 2026, 00:00. Zone: America/New_York.
Result
2026-01-01T05:00:00Z
This is 05:00 UTC on 1 January. Midnight UTC would be a different target, five hours earlier. People opening the shared countdown count toward the same instant.
A calendar day can contain 23 elapsed hours
Start with
From 7 March 2026 at noon to 8 March 2026 at noon, both in New York.
Result
0 full 24-hour days and 23 hours.
The clock moves forward during this interval. The countdown shows elapsed time in 24-hour days, while the days-between-dates calculator would report one calendar day.
Common questions
Why does a countdown disagree with a calendar-day count?+
The countdown measures elapsed seconds and groups them into 24-hour days. Calendar-day counting follows date boundaries. Daylight saving and the target time of day can make those totals differ.
Can friends see the same countdown in another country?+
Yes, when they open the optional share link. The link stores a resolved target instant and the event’s zone. Keep your device clock accurate, since each browser uses its own current time to show what remains.
What is included in a share link?+
The event title, target instant and zone are readable in the URL fragment. Use a title you are comfortable sharing. Countdown details stay in the page unless you deliberately create a link.